package protocol

import (
	"io"
)

// ----------------------------------------------------------------------------
// Codec
// ----------------------------------------------------------------------------

// Codec creates a CodecRequest to process each request.
type Codec interface {
	// NewRequest is constructor of new request object
	// error io.ErrUnexpectedEOF or io.EOF
	NewRequest(rc io.Reader) (CodecRequest, error)
}

// CodecRequest decodes a request and encodes a response using a specific
// serialization scheme.
type CodecRequest interface {
	// Reads the request and returns the RPC method name.
	Method() (string, error)
	// Reads the request filling the RPC method args.
	ReadRequest(interface{}) error
	// Writes the response using the RPC method reply.
	WriteResponse(io.Writer, interface{}) error
	// Writes an error produced by the server.
	WriteError(w io.Writer, status int, err error) error
}